Yarn trimming mechanisms



July 1s; 1967 Q P, BASTUSCHECK ET AL 3,331,220

YARN TRIMMING MECHANI SMS 2 Sheets-Sheet 1 Filed April 26, 1965 s. ...1@f ,a .B om

INVENTORS C n g www Y M B w d W 1 WM 6 A fag M um n f Omoo., GW

YARN TRIMMING MECHANISMS Filed April 26, 1965 2 Sheets-Sheet 2 g uw, .9l/vVENToRs.

Clifford ,-P. Basfuscheck, g Donald J. Coughenour and George W.Rohrbaugh.

wao, a@ A wfg/maag ATTORNEY United States Patent O 3,331,220 YARNTRIMMING MECHANISMS Clifford P. Bastuscheck and George W. Rohrbaugh,State College, and Donald J. Coughenour, Boalsburg, Pa., assignors toThe Singer Company, New York, N.Y., a corporation of New Jersey FiledApr. 26, 1965, Ser. No. 458,835 Claims. (Cl. 66-134) The presentinvention relatesjo a trimming mechanism and more particularly to a yarntrimming mechanism especially adapted for trimming the ends of areinforcing yarn in a circular hosiery knitting machine.

The objects of this invention is to provide a yarn trimming mechanismthat is inexpensive and at the same time is dependable, durable, andefiicient in operation, that is economical not only in that the powerrequirements are at a minimum but also in that the heat propagatedthereby is at a minimum, that is suiciently fast-acting to sever yarnsin a circular hosiery knitting machine that is operating at normalspeeds, and that is capable of being designed into such a machine inview of the space limitations thereof.

Having in mind the above and other objects that will be evident from anunderstanding of this disclosure, the invention comprises the devices,combinations and arrangements of parts as illustrated in the presentlypreferred embodiment of the invention which is hereinafter set forth insuch detail as to enable those skilled in the art readily to understandthe function, operation, construction and advantages of it when read inconjunction with the accompanying drawings in which:

FIG. l is a fragmentary sectional view of a knitting machine providedwith a trimmer in accordance with this invention,

FIG. 2 is a top plan view of the trimmer of FIG. 1,

FIG. 3 is a vertical sectional view longitudinally of the trimmer ofFIG. 1,

FIG. 4 is a transverse sectional view taken substantially on the line 44 of FIG. 1,

FIG. 5 is a detail View in unit per se.

With reference to the drawings, there is illustrated a fragmentaryportion of a circular knitting machine and particularly the rotaryneedle cylinder 1 having needle grooves 2 longitudinally in theperiphery thereof in which the needles 3 are mounted for endwisesliding. Rotating with the needle cylinder 1 is a sinker ring 4 in whicha plurality of sinkers 5 `are mounted for sliding radially relative tothe axis of the needle cylinder 1. To actuate the sinkers 5, there isprovided a stationary sinker cap 6 having a cam groove that receives thebutts 7 of the sinkers. The needles 3 are adapted to be raised andlowered in the needle grooves 2 by a needle cam 3a cooperating with butt3b of the needle. The trimmer in accordance with this invention isadapted to sever the knitting yarns at a point as closely adjacent totheI needles as is practical.

The trimmer, which is generally indicated at 8, is mounted upon a post 9upstanding from the frame of the machine. The means for mounting thetrimmer on the post comprises a mounting plate 10 secured to the top ofthe post 9 by a screw 11 and having a laterally extending portion 12upon which a pivot plate 13 is mounted by a screw 14. The pivot plate 13has a pair of spaced upstanding lugs 15 between which is mounted thedepending block portion 16, FIG. 4, of the body portion or frame 17 oftheptrimmer. A pivot pin 18 is secured in the lug 16, as by a set screw19, `and the ends thereof are pivotally mounted in the lugs 15. The pin18 has a head 20 at one end thereof and a nut 21 threaded into the otherend. The pin 18 and thus the entire trimmer is pivotally biasedclockwise, as seen in FIGS. 1 and 3,

perspective of the trimmer by a torsion spring 22 coiled about the head20 of the pin 18 and anchored at its opposite ends in a slot 23 in theend of the head 20 and in a hole in the pivot plate 13. The spring 22biases the body portion 17 of the trimmer into a stop position asdetermined by 'adjustable stop screws 24 threaded through a portion ofthe body portion 17 and adapted to engage the top of the sinker cap 6,thereby positioning the trimmer vertically relatively to the needles 3.

Secured, for example as by brazing to the body portion 17 at the topthereof is an open-ended tube 25 which is disposed with the axisthereof, substantially normal to the axis of the pin 18 and in a planeradially of the needle cylinder 1. Mounted in the tube 25 is the trimmerunit 26 (shown per se in FIG. 5) which comprises an electromechanicaltransducer 27 and an acoustical transformer or amplifier 28 commonlycalled a horn. The transducer 27 is an electrically actuated generatorof endwise oscillation or vibrations of high and preferably ultrasonicfrequencies, and in the illustrated embodiment of the inventioncomprises a piezoelectric crystal 29 that is connected by wires 30 witha source of electric power of suitable frequency. A sleeve 31 ofinsulation surrounds the end of the crystal at the connection of thewires 30. The transformer 28 is of a strong resilient metal, for exampleK-Monel, and comprises a first portion 32 secured at one end as by anepoxy resin directly to the end of transducer 27 and a second portion 33extending from the opposite end thereof. The portions 32 and 33 arepreferably cylindrical with the diameter of the first portion 32 beingsubstantially equal to that of the crystal 27 and the diameter of thesecond portion being substantially less. The length of the first portion32 is made equal to one-quarter of the wave length of sound in thematerial of which the transformer 28 is formed at the frequencygenerated by the transducer 27. The length of the second portion 33 ofthe transformer is three times that of the first portion 32.

For mounting the trimmer unit 26 in the tube 25 for endwise sliding intoand out of operative position with respect to the needles 3, there isprovided a sleeve 35 secured as by brazing to the rst portion 32 of thetrans-l former at the end thereof adjacent to the second portion 33.This point, being spaced at a distance equal to onequarter wave lengthfrom the end that is connected to the transducer 27 is at a node pointat which there is no endwise vibration of the first portion 32 of thetransformer. The sleeve 35 has an outside diameter such as to be snuglybut slidably received within the tube 25. The trimmer unit 26 issupported at a second point within the tube 25 by a rubber O-ring 36that surrounds the crystal 27.

The free end 37 of the second portion 33 of the transformer 28 is formedwith a cutting edge 38 that is adapted to cooperate with the cuttingedge 39 of anvil 40. The anvil 40 is carried by a collar 41 that isfixed on the second portion 33 of the transformer at a nodal planethereof, which in the disclosed embodiment is at one-quarter wave lengthfrom the cutting edge 38. To bias the cutting edge 39 of the anvil 40against the cutting edge 38, there is provided a relatively rigidbracket 42 carried by the collar 41 and into which is threaded the endof an adjusting screw 43.

The trimmer unit 26 is adapted to be advanced into and to be retractedfrom its operating position relative to the needles 3 by means of acable 44 that is enclosed within a flexible but noncompressible sheath45 which is connected at its end adjacent to the trimmer to a sleeve 46that telescopically receives a stud 47 secured to a plate 48. Theopposite end (not shown) of the sheath 45 is connected to a stationarypoint of the frame. The cable 44 extends freely through the sleeve 46,stud 47 and plate 48 and at its end is connected to the body 17 of thetrimmer by a block 49 secured to the end of the cable and seated in abore in the body 17 and held therein by a removable plate 50. Two rods51 and 52 are connected to the plate 48 by screws 53 and extend normaltherefrom and along and parallel to the tube 25. The rods 51 and 52 aremounted for endwise sliding in lugs 54 integral with the body 17,thereby serving to support the plate 48. At their ends the rods 51 and52 are provided with blocks 55 secured on the reduced ends thereof as byset screws 56. The blocks have inwardly extending trunnions 57, FIG. 4,that extend through slots 58 in the tube 25 and into apertures 59 in thecollar 35, thereby coupling the rods 51 and 52 to the trimmer unit 26.The slots 58 are elongated endwise of the tube 25 to permit motion ofthe trimmer unit 26 endwise thereof. The sleeve 46 is coupled to theplate 48 lby a trip mechanism 60 whereby when the sleeve is urgedforwardly, the plate 48 and thus the rods 51 and 52 and the trimmer unit26 will be moved into trimming position. The cable 44 is adapted to betensioned by the usual pattern cam of the machine. The sleeve 46 isurged forwardly by the sheath when tension is applied to the cable 44,thereby tending to straighten and to decrease the length of the path ofthe sheath. The rod 52 is provided with a collar 61 that is adapted toabut 'the end of the tube 25, thereby limiting the forward movement ofthe trimmer unit 26. When tension in the cable 44 is relaxed, thetrimmer unit 26 is returned to its retracted position by a spring 62that surrounds a rod 63 that is secured at one end to the plate 48 andat its other end telescopes into a bore 64 in the lug 16 of the body 17.The bore 64 is of sufficient depth to provide for relative motionbetween the Ibody 17 and the rod 62 when the trip 60 is released.Tension is adapted to be applied to the cable 44 at the desired point inthe knitting cycle by the usual master cam (not shown) of the machine.

The trip mechanism 60 is designed to prevent a smashup of the needles 3by retracting the trimmer unit 26 from its operative position in theevent that a needle 3 is not properly lowered, as when the butt thereofis broken. The trip mechanism comprises a lever arm 65 pivotally mountedintermediate its ends on the plate 48 by a pivot pin 66, FIG. 1, thelever arm 65 'being biased about the pin 66 in a clockwise direction asseen in FIG. 2 by a spring 67. On the one end of the lever arm 65 is aroller 68, FIG. 2, that engages the end of the sleeve 46 and againstwhich it is held by the spring 62. The opposite end of the lever arm 65is provided with an upstanding pin 69. The pin 69 isadapted to beengaged by an arm 70 that is carried by a bar 71 which in turn iscarried by a rod 72 that is pivotally mounted by means of a block 73 ona pin 74 extending through an elongated slot 75 in the tube 25 andthreaded into a aperture 76 in the sleeve 35. The rod 72 has a needleengaging end 77 that extends toward and, with the trimmer unit 26advanced to its operative position, is disposed closely adjacent to thepath of the ends of the needles immediately in front of the trimmer unitat the cutting edge 38. Thus, the end 77 is adapted to be engaged by aneedle which is not properlyV withdrawn and when engaged, pivots therods 72 and thus the arm 70 to engage the pin 69 and thus to pivot thelever arm 65 and to release the roller from engagement with the end ofthe sleeve 46. When so released, the spring 62 forces the plate 48outwardly toward the sleeve 46, thereby effecting throw-out of thetrimmer unit 26.

Numerous alterations of the structure herein disclosed will suggestthemselves to those skilled in the art. However, it is to be understoodthat the present disclosure relates to a preferred embodiment of myinvention which is for purposes of illustration only and not to beconstrued as a limitation of the invention. All such modifications whichdo not depart from the spirit of the invention arek intended to beincluded within the scope of the appended claims.

What is claimed is:

1. A trimming mechanism Yincluding a trimmer unit comprising anelectromechanical transducer adapted to generate endwise oscillations ofhigh frequency, an acoustical transformer secured to said transducer forreceiving endwise oscillations therefrom and for amplifying suchoscillations, said transformer having a free end formed as a cuttingedge, an anvil having a cutting edge and means for mounting said anvilon said transformer at a node point with the cutting edge thereofcooperating with the cutting edge at the free end of said transformerfor severing yarns between said cutting edges.

2. A trimming mechanism in accordance with claim 1 in which the meansfor mounting said anvil on said transformer comprises a collar securedto said transformer at a node point, and there is provided means f-oradjusting t-he cutting edge of said anvil relatively to the cutting edgeat the end of said transformer comprising a bracket carried by saidcollar and an adjusting screw cooperating with said bracket and anvil.

3. A yarn trimming mechanism for a knitting machine comprising a bodyadapted to be mounted on the machine, a trimmer unit, land means formounting said trimmer unit on said body for movement into and out of anoperative position with respect to the needles of the machine, saidtrimming unit comprising an electrome# chanical transducer adapted togenerate endwise oscillations of high frequency, an acousticaltransformer secured to said transducer for receiving endwiseoscillations therefrom and for amplifying such oscillations, saidtransformer having a free end for-med as a cutting edge, an anvil havinga cutting edge, and means for mounting said anvil on said transformer ata node point with the cutting edge thereof cooperating with the cuttingedge at the free end of said transformer for severing yarns between saidcutting edges.

4. A yarn trimmer mechanism in accordance with claim 3 in which saidmeans for mounting said trimmer unit on said body comprises a tube onsaid body and receiving said trimmer unit, longitudinally thereof, and acollar slidably mounted in said tube and secured to said tri-mmer unitat a node point of said transformer thereof.

5. A yarn trimming mechanism in accordance with claim 4 in which saidtransformer comprises two portions each of which are uniform incross-section with the cross-section of the one section adjacent to thetransducer being substantially larger than the cross-section of theother section, and there being two different node points along saidtransformer with said collar for mounting the trimmer unit in said tubebeing secured thereto at the node point nearer to said transducer andthe means for mounting the anvil on said transformer being disposed atthe other one of said two node points.

References Cited UNITED STATES PATENTS 2,651,148 9/1953 Carwile.

2,714,890 8/ 1955 Vang.

2,825,186 3/1958 Palush S10-8.3 X 2,895,064 7/1959 Hoff et al. 310-293,027,690 4/1962 Roney B10-8.3 X 3,086,288 4/ 1963 Balamuth et al.30-272 3,206,948 9/ 1965 Della Bella et al. 66-145 3,246,489 4/ 1966Della Bella 66-145 X MERVIN STEIN, Primary Examiner. W. C. REYNOLDS,Assistant Examiner.

1. A TRIMMING MECHANISM INCLUDING A TRIMMER UNIT COMPRISING ANELECTROMECHANICAL TRANSDUCER ADAPTED TO GENERATE ENDWISE OSCILLATIONS OFHIGH FREQUENCY, AN ACOUSTICAL TRANSFORMER SECURED TO SAID TRANSDUCER FORRECEIVING ENDWISE OSCILLATIONS THEREFROM AND FOR AMPLIFYING SUCHOSCILATIONS, SAID TRANSFORMER HAVING A FREE END FORMED AS A CUTTINGEDGE, AN ANVIL HAVING A CUTTING EDGE AND MEANS FOR MOUNTING SAID ANVILON SAID TRANSFORMER AT A NODE POINT WITH THE CUTTING EDGE THEREOFCOOPERATING WITH THE CUTTING EDGE AT THE FREE END OF SAID TRANSFORMERFOR SEVERING YARNS BETWEEN SAID CUTTING EDGES.